In the reaction HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq), which ions are spectator ions in the complete ionic equation?

• A. Na^+ and Cl^-
• B. H^+ and OH^-
• C. Na^+ and OH^-
• D. H^+ and Cl^-

Answer: (A)

Verified step by step guidance

1. Write the balanced molecular equation: \(\mathrm{HCl(aq) + NaOH(aq) \rightarrow H_2O(l) + NaCl(aq)}\).
2. Write the complete ionic equation by dissociating all strong electrolytes into their ions: \(\mathrm{H^+(aq) + Cl^-(aq) + Na^+(aq) + OH^-(aq) \rightarrow H_2O(l) + Na^+(aq) + Cl^-(aq)}\).
3. Identify the ions that appear unchanged on both sides of the complete ionic equation. These ions do not participate in the formation of water and remain in solution.
4. Recognize that \(\mathrm{Na^+}\) and \(\mathrm{Cl^-}\) ions are present on both sides of the equation without change, so they are the spectator ions.
5. Confirm that \(\mathrm{H^+}\) and \(\mathrm{OH^-}\) ions react to form water, so they are not spectator ions.